L-tyrosine, also known as tyrosine, is a nootropic supplement that enhances your brain, mood, and stress response. Tyrosine is a precursor for three important neurotransmitters which are dopamine, norepinephrine, and adrenaline. Dopamine can help for mood and motivation. Norepinephrine can help for muscle recovery and blood flow. Adrenaline can help for focus and drive.